Little detailed information exists concerning reproduction in most mites and ticks. We propose to investigate various aspects of reproduction in acarines of public health importance. These species represent hard ticks (Ixodidae: Metastriata and Prostriata), soft ticks (Argasidae) and bird mites (Dermanyssidae). Four species will be used to varying degrees depending on specific experiments. Overall objectives include study of (1) growth and differentiation of acarine reproductive systems; (2) histological correlation of growth and other responses of non-reproductive organ systems with those of reproductive systems; (3) role of nutrition in reproduction; (4) endocrine factors which may affect reproduction (in vivo); (5) factors regulating control of reproduction (in vitro); (6) spermatophore production and mating behavior; (7) effects of various parts of mating on oogenesis and oviposition; (8) artificial insemination; (9) effects of a radiomimetic compound (metepa) on male reproductive development and fertility.